High voltage pulse generators have been used to generate discharge pulses, such as spark and/or plasma discharges, between electrodes attached to the pulse generator. In one application, a high voltage pulse generator has been used in spark induced breakdown spectroscopy (SIBS) based instruments. In some SIBS instruments, an intense electrical discharge between two electrodes creates plasma from the gas flowing between the electrodes, where the gas may include aerosolized particles of interest. Optical detectors then measure properties of the resulting plasma with the aim of quantifying the identities and concentrations of the aerosolized particles. Examples of SIBS and other similar spectroscopy techniques are described, for example, in the article entitled “Historical Advances in Spark Emission Spectroscopy” by J. P. Walters, Volume 23, Number 4, 1969, Applied Spectroscopy, in the article entitled “Preliminary correlations of feature strength in spark-induced breakdown spectroscopy of bioaerosols with concentrations measured in laboratory analyses” by M. S. Schmidt and A. J. R. Bauer, Volume 49, Number 13, 2010, Applied Optics, and in U.S. Pat. Nos. 3,749,975, 3,973,167; 4,393,327; 4,766,318; and 6,034,768, all of which are fully incorporated herein by reference. Other applications for pulse generators include spark plugs, underwater acoustics, stun guns, and explosive discharges as described in U.S. Pat. Nos. 3,093,770; 5,215,066; and 6,999,295.
One problem that arises in devices that produce electrically induced spark and/or plasma discharges between electrodes is the degradation of the electrodes. The electrodes may be deformed and eroded continuously as pulses are passed through them until eventually the electrodes are no longer useful and must be replaced. Some existing devices have attempted to address this problem by using robust materials for the electrodes. In other existing devices, one of the electrodes is made from the material to be analyzed and is thus eroded as it is analyzed. High voltage pulse generators may also include other power circuitry elements that tend to wear out with extended use.
When electrodes and/or other components are susceptible to degradation or failure with extended use, existing methods for monitoring usage have been inadequate to determine when such electrodes or components should be replaced. As a result, the devices (e.g., SIBS instruments or spark plugs) in which the pulse generators are used may degrade or even stop functioning unexpectedly and without warning.
Another problem that arises is the unique challenge of designing a high voltage pulse generator with a small enough form factor to be viable, for example, for field portable applications. Providing high voltage circuitry capable of generating discharge pulses of sufficiently high pulse energy and frequency within a small space often leads to malfunctions of the power circuitry elements and/or control circuitry. To generate an electrical discharge pulse, some existing pulse generators discharge a charged capacitor into the primary side of a high voltage step-up transformer such that a corresponding high voltage pulse is generated at the secondary side of the transformer. The ability to decrease the size of a pulse generator using this existing circuit design is limited. High voltage pulse generators may also be required to meet certain electro-magnetic interference and compatibility (EMI/EMC) and environmental requirements.